1 Explain that a population pyramid shows the age and sex structure of a population. 2  Point to the horizontal bars, which show the percentage (or the absolute number) of males and females in each age group. 3  Have students interpret the chart.
1 Although they range from $150-$400 or more, a large capacity (25-70 pints) dehumidifier for a basement (the dampest portion of most homes) or other large area averages $200-$300.
If the drain fails, you may have a bulk water problem in the crawl space. If it's a small crawl space, a standard dehumidifier that you can buy for $200 to $300 may be sufficient. For medium to large crawl spaces, however, it's best to go with a more robust model, like the ones made by Therma-Stor. Their Santa Fe line is made for basements and crawl spaces.